Like the iOS App Store, the Mac App Store is curated by Apple to ensure that apps run properly and that they don't violate any App Store rules or guidelines. However, apps can still be purchased and installed from locations besides the Mac App Store -- an important difference from the iOS App Store, which maintains a closed environment for iOS app installation.
These third-party stores mean good news for Leopard and Tiger users, who can't access the Mac App Store. Even better, there are several easy-to-browse marketplaces that are free of Apple's App Store terms and conditions, and some easy-to-manage update tools are available.
Bodega is essentially a Mac App Store app. It has a storefront feel and allows you to browse, purchase, and download new apps and update already-installed apps (whether installed via Bodega or not) from a simple and intuitive interface. The selection of apps available in Bodega is pretty good, and like the Mac App Store, it's organized by categories and lets you see new releases, staff picks, and the top free and paid downloads.
There are many Mac catalogs worth visiting on the Web. Almost all are broken down by category and offer user ratings and reviews, and some also offer staff recommendations. Some of the top Mac software catalogs include MacUpdate, Pure Mac, Cnet's Mac Software list (formerly Versiontracker.com), FreeMacWare, MacShareware.com, App Donkey, and Mac Softpedia. Mac.AppStorm isn't an app catalog, but it is a great resource for Mac software information and reviews.
I mentioned that Bodega offers some automatic update capabilities, but there are several tools that can constantly track your installed Mac software (commercial, shareware, and free/open source) and alert you to updates. Some of the better options include MacUpdate Desktop, AppFresh, and MacKeeper. MacUpdate Desktop and AppFresh are free and focus just on update management, while MacKeeper is a $38 tool that offers a range of other Mac utility features, including antivirus protection, backup, file encryption, and disk space management tools.
Finally, another potential alternative to Apple's Mac App Store is brewing. Cydia, the unofficial app store for jailbroken iOS devices and apps not approved by Apple, has announced plans to create Cydia for Mac. The exact purpose of creating the store is a little unclear, since Mac OS X will remain an open platform where users can install any apps they want (no jailbreaking required), but once up and running, it will offer users an additional storefront-style option.
The tools in this list may fall short of what's coming in Mac OS X Lion, but they do approximate some of the Lion features we've glimpsed. Some offer advantages that we may not see in Lion, such as character-based gestures and the ability to fully customize individual spaces. Regardless of how they compare to the upcoming Lion, they offer great benefits to Mac users in the here and now.
Ryan Faas is a freelance writer and technology consultant specializing in Mac and multiplatform network issues. He has been a Computerworld columnist since 2003 and is a frequent contributor to Peachpit.com. Faas is also the author of iPhone for Work (Apress 2009). You can find out more about him at www.ryanfaas.com and follow him on Twitter (@ryanfaas).